strange Laptop to Router thruput speeds

I've got a Linksys Wireless-N home network (WRT300N router & WPC300N
adapter).

My router is in the living room and the laptop is 25ft away in the
bedroom. Neither unit gets moved yet internal LAN speeds vary
tremendously within a matter of minutes. For example, using IPERF, I
got these test results from readings taken 5 minutes apart:

[1868] local 192.168.1.101 port 1443 connected with 192.168.1.102 port
5001
[ ID] Interval Transfer Bandwidth
[1868] 0.0-10.0 sec 32.1 MBytes 26.9 Mbits/sec
.................................................. .................................................. ........................
[1868] local 192.168.1.101 port 2461 connected with 192.168.1.100 port
5001
[ ID] Interval Transfer Bandwidth
[1868] 0.0-10.0 sec 8.98 MBytes 7.51 Mbits/sec

"umo" <shoreke@yahoo.com> hath wroth:

>I've got a Linksys Wireless-N home network (WRT300N router & WPC300N
>adapter).
>
>My router is in the living room and the laptop is 25ft away in the
>bedroom. Neither unit gets moved yet internal LAN speeds vary
>tremendously within a matter of minutes. For example, using IPERF, I
>got these test results from readings taken 5 minutes apart:

- What exact IPerf command line did you use?
- UDP or TCP on the server side?
- You're testing from the laptop to/from what computah? Another
wireless computer or a wired desktop? (It should be a desktop).

>[1868] local 192.168.1.101 port 1443 connected with 192.168.1.102 port 5001
>[ ID] Interval Transfer Bandwidth
>[1868] 0.0-10.0 sec 32.1 MBytes 26.9 Mbits/sec
>................................................. .................................................. ........................
>[1868] local 192.168.1.101 port 2461 connected with 192.168.1.100 port 5001
>[ ID] Interval Transfer Bandwidth
>[1868] 0.0-10.0 sec 8.98 MBytes 7.51 Mbits/sec

Incidentally, I'm getting about the same thing with my WRT54GS (with
DD-WRT v23 sp2) from my desktop to my laptop. My guess(tm) is that
you're only connected at 54MBits/sec. Try moving the laptop close to
the router and see if it improves.

However, before you start playing with the wireless part, move the
laptop to near the router, turn *OFF* the wireless, and plug in
directly to the router with a CAT5 ethernet cable. If you get a
100baseT-FDX connection, you should be able to do about wire speed on
the IPerf benchmark or about 70Mbits/sec. If you can't do that, then
something is wrong with the "other" computer.

As for variations in performance, that's reflections and interference.
As the wireless connection speed goes up, the sensitivity to
interference goes up along with it. Also, if you have the 802.11b
compatibility mode enabled, you'll see a tremendous performance hit
when even one 802.11b packet comes drifting your way.
<http://wireless.wikia.com/wiki/Wi-Fi#Performance_and_Speed>



--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann <jeffl@comix.santa-cruz.ca.us> hath wroth:

>"umo" <shoreke@yahoo.com> hath wroth:

>>[1868] local 192.168.1.101 port 1443 connected with 192.168.1.102 port 5001
>>[ ID] Interval Transfer Bandwidth
>>[1868] 0.0-10.0 sec 32.1 MBytes 26.9 Mbits/sec
>>................................................ .................................................. .........................
>>[1868] local 192.168.1.101 port 2461 connected with 192.168.1.100 port 5001
>>[ ID] Interval Transfer Bandwidth
>>[1868] 0.0-10.0 sec 8.98 MBytes 7.51 Mbits/sec

Notice the two lines from your test:
>>[1868] local 192.168.1.101 port 1443 connected with 192.168.1.102 port 5001
>>[1868] local 192.168.1.101 port 2461 connected with 192.168.1.100 port 5001
Why is the target machine .102 in the first line, and .100 in the 2nd.
Why did the IP address change in 5 minutes? Why the funny port
numbers? What exactly are you doing?


This is what I get using a wired PIII/1GHz with W2K as a server and a
wireless HP Ze2000 laptop for the client with a 54Mbit/sec connection
to a WRT54GS with DD-WRT v23 SP2.

>iperf -c 192.168.1.146 -r
>------------------------------------------------------------
>Server listening on TCP port 5001
>TCP window size: 8.00 KByte (default)
>------------------------------------------------------------
>Client connecting to 192.168.1.146, TCP port 5001
>TCP window size: 8.00 KByte (default)
>------------------------------------------------------------
>[828] local 192.168.1.11 port 2207 connected with 192.168.1.146 port 5001
>[ ID] Interval Transfer Bandwidth
>[828] 0.0-10.0 sec 27.5 MBytes 23.1 Mbits/sec
>[800] local 192.168.1.11 port 5001 connected with 192.168.1.146 port 1088
>[ ID] Interval Transfer Bandwidth
>[800] 0.0-10.0 sec 29.3 MBytes 24.6 Mbits/sec


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann <jeffl@comix.santa-cruz.ca.us> hath wroth:

>However, before you start playing with the wireless part, move the
>laptop to near the router, turn *OFF* the wireless, and plug in
>directly to the router with a CAT5 ethernet cable. If you get a
>100baseT-FDX connection, you should be able to do about wire speed on
>the IPerf benchmark or about 70Mbits/sec. If you can't do that, then
>something is wrong with the "other" computer.

Well, 70Mbits/sec might be a bit pessimistic. I'm getting 94Mbits/sec
with a direct 100baseTX-FDX ethernet connection:

>iperf -c 192.168.1.114 -r
>------------------------------------------------------------
>Server listening on TCP port 5001
>TCP window size: 8.00 KByte (default)
>------------------------------------------------------------
>Client connecting to 192.168.1.114, TCP port 5001
>TCP window size: 8.00 KByte (default)
>------------------------------------------------------------
>[828] local 192.168.1.11 port 2226 connected with 192.168.1.114 port 5001
>[ ID] Interval Transfer Bandwidth
>[828] 0.0-10.0 sec 112 MBytes 93.7 Mbits/sec
>[868] local 192.168.1.11 port 5001 connected with 192.168.1.114 port 1111
>[ ID] Interval Transfer Bandwidth
>[868] 0.0-10.0 sec 113 MBytes 94.6 Mbits/sec

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Server side: iperf -s

Client side: iperf -c 192.168.1.102...1st test
Client side: iperf -c 192.168.1.100...2nd test

Wireless connection speed 161Mbs.

Test is from laptop to TCP wired desktop.

Latop within a foot of router results in 40Mbs thruput.

Wired connection is 100Mbs.

Router was rebooted before 2nd test resulting in assignment of a
different IP address.

802.11b compatibility mode is enabled. Turning it off results in very
slow speeds. Not sure why since I have Linksys wireless-N notebook
adapter and Linksys wireless-N router.

"umo" <shoreke@yahoo.com> hath wroth:

>Server side: iperf -s
>
>Client side: iperf -c 192.168.1.102...1st test
>Client side: iperf -c 192.168.1.100...2nd test

So .101 is the laptop. Which is the wired desktop?
Do you have TWO desktops?

>Wireless connection speed 161Mbs.

TomsNetworking got about 75 Mbits/sec thruput on a simulator with the
WRT-300N:
<http://www.smallnetbuilder.com/wireless/wireless-features/draft_11n_revealed_part1/page6.html/>
<http://images.tomshardware.com/2006/06/01/draft_802/draft_11n_all_dn_throughput_compare_annotated_big. png>

>Test is from laptop to TCP wired desktop.

Which is the desktop. .100 or .102 ? Do you have two desktops?

>Latop within a foot of router results in 40Mbs thruput.
>
>Wired connection is 100Mbs.

Did you measure the direct connect speed? See my results I just
posted.

>Router was rebooted before 2nd test resulting in assignment of a
>different IP address.

Muddle? The router is suppose to have a fixed IP address and assign
IP's to the clients. What has a different IP address? I can't tell
from your statement.

Sorry to be a pest, but I'm lost with 3 IP addresses and no clue what
address belongs to what device. You also seem to have one extra
device.

>802.11b compatibility mode is enabled. Turning it off results in very
>slow speeds. Not sure why since I have Linksys wireless-N notebook
>adapter and Linksys wireless-N router.

That's all wrong. Turning off 802.11b compatibility should improve
the speed, not reduce it. No clue why, but my guess is that you have
some kind of setup, config, or wiring problem.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Router ip address is static...192.168.1.1

Laptop ip address remained the same....192.168.1.101

I have two desktops. Only one desktop with IPERF installed. I
disconnected the 2nd desktop just before rebooting the router. This is
why the ip of desktop, running server mode IPERF, was changed from .102
to .100

(Before reboot of router) desktop ip...192.168.1.102
(After reboot of router) desktop ip...192.168.1.100

Both these commands were issued from wireless laptop(.101) to desktop
(iperf -c 192.168.1.102)...1st test...26.9 Mbits/sec
(iperf -c 192.168.1.100)...2nd test...7.51 Mbits/sec

wired laptop connection thruput...90Mbs

I might need to tweak Network mode, CTS Protection mode and Channel
settings in my Router Configuration. Currently 5 other wireless
networks are within broadcast range of my router. It looks like a lot
of my neighbors are into wireless networking.

"umo" <shoreke@yahoo.com> hath wroth:

>Router ip address is static...192.168.1.1
>
>Laptop ip address remained the same....192.168.1.101
>
>I have two desktops. Only one desktop with IPERF installed. I
>disconnected the 2nd desktop just before rebooting the router. This is
>why the ip of desktop, running server mode IPERF, was changed from .102
>to .100
>
>(Before reboot of router) desktop ip...192.168.1.102
>(After reboot of router) desktop ip...192.168.1.100
>
>Both these commands were issued from wireless laptop(.101) to desktop
>(iperf -c 192.168.1.102)...1st test...26.9 Mbits/sec
>(iperf -c 192.168.1.100)...2nd test...7.51 Mbits/sec

The way I read this is your wireless laptop gets 27Mbits/sec to 102
desktop and 7.5 to 100 desktop. The obvious deduction would be that
something is broken in the WIRED connection to 102 desktop. Possibly
a broken cable or NWAY mismatch. Have you tried the speed between the
two desktops? My guess(tm) is that the 100 desktop is stuck in
10baseT-HDX mode, which yields about 7Mbits/sec thruput. Check the
100 computer network card settings and diagnostics.

>wired laptop connection thruput...90Mbs

Laptop to which desktop? Try it to both desktops. I think you'll be
suprised. (Please work on being more specific.)

>I might need to tweak Network mode, CTS Protection mode and Channel
>settings in my Router Configuration.

Those will help if you have interference, but I don't think that's the
problem.

>Currently 5 other wireless
>networks are within broadcast range of my router. It looks like a lot
>of my neighbors are into wireless networking.

The surest sign of success is pollution. Wi-Fi is successful.
--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann <jeffl@comix.santa-cruz.ca.us> hath wroth:

>>Both these commands were issued from wireless laptop(.101) to desktop
>>(iperf -c 192.168.1.102)...1st test...26.9 Mbits/sec
>>(iperf -c 192.168.1.100)...2nd test...7.51 Mbits/sec
>
>The way I read this is your wireless laptop gets 27Mbits/sec to 102
>desktop and 7.5 to 100 desktop. The obvious deduction would be that
>something is broken in the WIRED connection to 102 desktop.

Argh. That should read:
The obvious deduction would be that something is broken in the WIRED
connection to 100 desktop.
^^^
--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558